Capsule-type medical device

ABSTRACT

A capsule-type medical device comprises a capsule main unit having functions for being inserted into the body cavity and performing medical acts such as taking images or the like. The capsule main unit comprises therein a magnet which is acted upon by external magnetism, and a spiral portion on the outer perimeter, so that rotating force acting upon the magnet is readily converted into a propelling force for propelling the capsule-type medical device. A flexible insertion portion which is long and small in diameter is provided to the capsule main unit to allow smooth progression through the body cavity, and the center of gravity of the device is placed upon the longitudinal center axis of the capsule main unit, thus facilitating smooth progression through the body cavity.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 11/702,871 filed on Feb. 6, 2007, which is a continuationapplication of U.S. application Ser. No. 10/395,745 filed on Mar. 24,2003 which claims benefit of Japanese Application No. 2002-84387 filedon Mar. 25, 2002, the entire contents of each of which are incorporatedby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a capsule-type medical device which ispassed through the body cavity and is capable of examination, therapy,and/or treatment.

2. Description of the Related Art

Capsule-type medical devices are known as medical devices which areswallowed by patients to pass through the body cavity tract, which canperform examination, therapy, and/or treatment.

Such capsule-type medical devices comprise treatment tools forperforming such medical treatment, such as a medication-depositing unitfor depositing medicine, treatment devices such as forceps or the like,treatment devices for performing incision or coagulation by ultrasonicor high-frequency means, and so forth, and are arranged to perform suchmedical treatment at an object portion in the body cavity tract.However, there are shortcomings within the capsule-type medical devices,such as requiring a long time to reach the object portion unless guidedthrough the body cavity tract.

To deal with this problem, Japanese Patent Publication No. 3017770discloses a capsule-type medical device comprising a magnet which ismagnetically manipulated by a magnet outside of the body of the subject.With the medical device described in Japanese Patent Publication No.3017770 (hereafter referred to simply as “No. 3017770”), an externaluniform magnetic field uniaxially acts upon magnets provided on theouter perimeter of a capsule main body in the vertical direction, sothat the capsule is guided through the body cavity tract withoutrotating, primarily. Also, an arrangement is also disclosed wherein analternating magnetic field is applied externally, so as to rotate themain body. However, efficiently propelling rotational motion of the mainunit is not easy.

Note that this No. 3017770 is equivalent to the Japanese PatentApplication with Application No. H2-109696 (filed on Apr. 25, 1990)which is cited as proof of prior application in the later-described U.S.Pat. No. 5,681,260.

On the other hand, with the capsule-type medical device described inJapanese Unexamined Patent Application Publication No. 2001-179700(hereafter referred to simply as “No. 2001-179700”), an externalrotating magnetic field acts triaxially on a magnet provided within thecapsule main unit in the vertical direction and horizontal direction, soas to gain propulsion by rotationally turning.

With the capsule-type medical device described in No. 2001-179700, athrust generating unit which obtains propulsion by rotating is providedin the capsule main unit. However, with the capsule-type medical devicedescribed in No. 2001-179700, no consideration has been given to theinternal structure of the capsule main unit with regard to rotations ofthe capsule main unit.

Accordingly, the capsule-type medical device described in No.2001-179700 may make useless motions such as rotating eccentrically(zigzagging), and accordingly take time to reach the object position inthe body cavity tract, rather than reaching the location smoothly.

Also, U.S. Pat. No. 5,353,807 discloses a configuration comprising aslender and flexible recovery member, a main unit disposed on the tipthereof for performing medical treatment, a coil provided on thecircumference to the main unit for guiding with an eternal magneticflux, and multiple propulsion plates provided on the recovering member,thereby enabling the direction of the main unit to be controlled by themagnetic polarity generated by the coil and the external magnetic flux,and further guiding the main unit through the body cavity by apropulsion plate provided on the recovering member.

This patent also discloses an arrangement of a main unit comprising aninternal magnet and battery, with the capsule not being provided withthe recovering member but rather guided by the external magnetic field.

However, with the arrangement described in this U.S. Patent, thedirection of the magnetic polarity generated by the coil or the magnetis in the longitudinal direction of the main unit, so smooth propulsionby an external magnetic field is not easy.

Also, U.S. Pat. No. 5,681,260 also discloses a device wherein anendoscope insertion portion or the like is magnetically guided throughthe body cavity, besides the embodiment relating to FIGS. 50 through 76Bcorresponding to No. 3017770.

The arrangement described in this U.S. patent has a similarconfiguration as that in No. 3017770, and smooth propulsion of theendoscope insertion portion or the like is not easy.

Further, the above-described preceding examples do not disclose contentscorresponding to the Claims of the Present Invention.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide acapsule-type medical device with little useless motions such aseccentric rotations, and which can be smoothly and readily propelledthrough body cavities.

It is another object of the present invention to provide a capsule-typemedical device which can be readily propelled through bending bodycavities.

To achieve these objects, the capsule-type medical device according tothe present embodiment comprises: a capsule main unit provided withfunctions for performing medical acts such as examination, therapy,and/or treatment; a magnet provided to the capsule main unit, formagnetically acting upon an external magnet outside of the subject; anda propulsion generating unit for converting rotational motion due to themagnet into propelling force; wherein the center of gravity of thecapsule main unit generally matches the center axis of the capsule mainunit in the longitudinal direction, thereby suppressing useless motionssuch as eccentric rotations, and enabling the capsule-type medicaldevice to be smoothly propelled through the body cavity to the targetposition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 14B relate to a first embodiment of a presentembodiment, wherein FIG. 1 is an overall configuration diagramillustrating a medical system with the first embodiment of the presentinvention;

FIG. 2 is a block diagram illustrating the configuration of theelectrical system according of the capsule-type medical device accordingto the first embodiment;

FIG. 3A is a cross-sectional diagram illustrating the configuration ofthe capsule-type medical device;

FIG. 3B is a frontal view illustrating the tip side of the arrangementshown in FIG. 3A;

FIG. 3C is a rear side view illustrating the rear end view of thearrangement shown in FIG. 3A;

FIG. 3D is a cross-sectional view illustrating the configuration of thecapsule-type medical device with the placement position of the magnetchanged;

FIG. 4A is an external explanatory diagram of a capsule-type medicaldevice for spreading a medicine;

FIG. 4B is an external view of the tip side of the capsule-type medicaldevice shown in FIG. 4A;

FIG. 5A is an explanatory diagram illustrating a capsule-type medicaldevice comprising a treatment tool storage unit and ultrasonic unit,wherein an elastic rubber cover having a spiral groove formed thereuponis detachably mounted to the capsule main unit;

FIG. 5B is a perspective view illustrating a part of the elastic rubbercover shown in FIG. 5A;

FIG. 6A is a cross-sectional diagram illustrating a capsule-type medicaldevice wherein a spiral portion provided to the rear side with regard tothe direction of progression is detachably provided, and an observationdevices is provided on the rear side with regard to the direction ofprogression;

FIG. 6B is a transverse cross-sectional diagram of the arrangement shownin FIG. 6A;

FIG. 7A is a cross-sectional view illustrating a capsule-type medicaldevice wherein multiple magnets are symmetrically disposed on the centeraxis of the capsule main unit in the longitudinal direction.

FIG. 7B is a transverse cross-sectional diagram of the arrangement shownin FIG. 7A;

FIG. 8A is a cross-sectional view illustrating a capsule-type medicaldevice wherein a spiral portion is detachably provided to the side atthe direction of progression, while an observation device is provided onthe rear side with regard to the direction of progression;

FIG. 8B is a cross-sectional diagram viewing the arrangement shown inFIG. 8A from the lower side of the drawing;

FIG. 9A is an explanatory diagram illustrating a capsule-type medicaldevice which is recovered by a recovery tool inserted through atreatment device insertion channel of an endoscope;

FIG. 9B is a transverse cross-sectional view at the tip side of thearrangement shown in FIG. 9A;

FIGS. 10A through 10C show a configuration wherein the capsule main unitcan be divided into the two parts of a portion where an observationdevice is disposed, and a portion where a magnet and spiral portion aredisposed, wherein FIG. 10A is an explanatory diagram illustrating acapsule-type medical device wherein the observation field of view of theobservation device is directed backwards;

FIG. 10B is an explanatory diagram illustrating a capsule-type medicaldevice wherein the observation field of view of the observation deviceis directed diagonally backwards;

FIG. 10C is an explanatory diagram illustrating a capsule-type medicaldevice wherein the observation field of view of the observation deviceis directed toward the side;

FIG. 11A is an explanatory diagram illustrating a capsule-type medicaldevice wherein a portion to which a spiral portion is provided is formedat a flexible insertion portion;

FIG. 11B is a transverse cross-sectional diagram of the arrangementshown in FIG. 11A;

FIG. 12A is an explanatory diagram illustrating a capsule-type medicaldevice provided with a ring-shaped magnet;

FIG. 12B is a transverse cross-sectional diagram of the arrangementshown in FIG. 12A;

FIGS. 13A through 13C illustrate a capsule-type medical device wherein aspiral portion is provided on the opposite side as to a flexibleinsertion portion on one end of the capsule main unit which is theprogression direction thereof in the longitudinal direction, whereinFIG. 13A is an explanatory diagram illustrating a capsule-type medicaldevice wherein the spiral portion is provided over almost the entirecircumference of the rear side of the capsule main unit;

FIG. 13B is an explanatory diagram illustrating a capsule-type medicaldevice wherein the spiral portion is provided diagonally over half ofthe rear side of the capsule main unit so as to enable diagonallyviewing in the backward direction;

FIG. 13C is an explanatory diagram illustrating a capsule-type medicaldevice wherein the spiral portion is provided over half of the rear sideof the capsule main unit so as to enable viewing sideways;

FIG. 14A is an explanatory diagram illustrating a capsule-type medicaldevice wherein the flexible insertion portion is detachably mounted tothe capsule main unit;

FIG. 14B is an explanatory diagram illustrating that the flexibleinsertion portion is bendable in the direction generally orthogonal tothe longitudinal direction;

FIGS. 15 through 21 relate to a second embodiment of the presentinvention, wherein FIG. 15 is an explanatory diagram illustrating acapsule-type medical device according to the second embodiment of thepresent invention;

FIG. 16 is an explanatory diagram illustrating the operations of thecapsule-type medical device shown in FIG. 15 within the body cavity;

FIG. 17 is an explanatory diagram illustrating the relation between thelength of the rigid portion of the capsule main unit and the length ofthe soft portion of the flexible insertion portion, with regard to themaximum diameter of the tubular body cavity organ;

FIG. 18 is an explanatory diagram of the operations of the capsule-typemedical device shown in FIG. 15 in bent or narrow portions or the likein tubular body cavity organs;

FIG. 19 is an external diagram illustrating a capsule-type medicaldevice wherein the spiral portion is formed by adhesion and fixing of awire-like material to the outer perimeter of the flexible insertionportion;

FIG. 20 is an explanatory diagram illustrating a capsule-type medicaldevice wherein the flexible insertion portion is configured withmultiple ball-shaped protrusions formed with ball-shaped magnets builttherein, formed thereupon;

FIG. 21 is an explanatory diagram illustrating the operations of thecapsule-type medical device shown in FIG. 20 inside the body cavity;

FIGS. 22 and 23 relate to a third embodiment of the present invention,wherein FIG. 22 is an explanatory diagram illustrating a capsule-typemedical device according to the third embodiment of the presentinvention; and

FIG. 23 is an explanatory diagram illustrating a modification example ofthe capsule-type medical device shown in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following is a description of embodiments of the present invention,with reference to the drawings.

First Embodiment

A first embodiment of the present invention will be described withreference to FIGS. 1 through 14B. The primary object of the presentembodiment is to provide a device and method wherein a capsule-typemedical device which performs medical actions can be rotated by externalmagnetism and thus be smoothly guided to a target portion or beside atarget portion; more specifically, to provide a device and methodwherein eccentric motion in rotation is suppressed so as to enableeffective or smooth propulsion to beside the target portion.

As shown in FIG. 1, a capsule-type medical device 1 exchanges radiowaves with a capsule control device (hereafter referred to simply as“control device”) 3 while passing through the body cavity tract of apatient 2, thus configuring a medical system 4 enabling examination,therapy, and/or treatment, under control of this control device 3.

The medical system 4 is for performing screening of the esophagus,duodenum, small intestine, large intestine, etc., by swallowing thecapsule-type medical device 1 with water or the like in the same waythat one would swallow medicine, following precleaning of the largeintestine (lavage of the intestinal tract). In the event that thecapsule-type medical device 1 passes through an area of interestrapidly, as with the duodenum for example, the medical system 4 takesimages at a rate of 10 frames per second, and on the other hand, takesimages at 2 frames per second for areas passed through slowly, such asthe small intestine, for example. The images that are taken aresubjected to necessary signal processing and digital compressionprocessing and then transmitted to the control device 3, and onlyinformation necessary is recorded as moving images so as to be used fordiagnosis.

Also, the medical system 4 is configured comprising a magnetic guidingdevice 5 which magnetically guides the capsule-type medical device 1.Note that FIG. 1 only shows the magnetic guiding device 5 schematically.The magnetic guiding device 5 is configured so as to form a rotatingmagnetic field which magnetically acts upon a later-described magnetprovided in a capsule main unit 1A of the capsule-type medical device 1.Also, the magnetic guiding device 5 is connected to the control device3, such that the control device 3 can control the direction of thegenerated rotating magnetic field.

The control device 3 comprises a personal computer main unit 11 havingfunctions for controlling the capsule-type medical device 1 and themagnetic guiding device 5, a keyboard 12 which is connected to thepersonal computer main unit 11 for inputting commands, data, etc., amonitor 13 which is connected to the personal computer main unit 11 fordisplaying images and the like, and an external antenna 14 which isconnected to the personal computer main unit 11 for transmitting controlsignals for controlling the capsule-type medical device 1 and receivingsignals from the capsule-type medical device 1.

The control device 3 is arranged such that the control signals forcontrolling the capsule-type medical device 1 and the magnetic guidingdevice 5 are generated based on key input from the keyboard 12 or by acontrol program stored in a hard disk or the like within the personalcomputer main unit 11.

The control signals for controlling the magnetic guiding device 5 aretransmitted from the external computer main unit 11 to the magneticguiding device 5 by a connecting cable not shown in the drawings.

The magnetic guiding device 5 generates the rotating magnetic fieldwherein the direction of the rotating magnetic field is controlled,based on the transmitted control signals. The capsule-type medicaldevice 1 is configured such that the rotating magnetic field generatedby the magnetic guiding device 5 magnetically acting upon thelater-described magnet rotates the capsule main unit 1A such that thedirection of progression of the capsule main unit 1A within the bodycavity is set by a later-described propulsion generating unit, and alsosuch that motive energy for propulsion of the capsule main unit 1A isgenerated.

On the other hand, the control signals for controlling the capsule-typemedical device 1 are modulated by carrier waves of a predeterminedfrequency at an oscillating circuit within the personal computer mainunit 11, and transmitted as radio waves from the external antenna 14.

The capsule-type medical device 1 receives the radio waves with alater-described wireless antenna 21, the control signals aredemodulated, and the demodulated control signals are output to thecomponent circuits and the like.

Also, the control device 3 receives signals including image informationof video signals and the like transmitted from the wireless antenna 21of the capsule-type medical device 1 with the external antenna 14, anddisplays images and the like on the monitor 13.

Next, a detailed configuration of the capsule-type medical deviceaccording to the present embodiment will be described with reference toFIGS. 2 through 3C. Note that the present embodiment is a capsule-typemedical device capable only of examination (observation).

The capsule-type medical device 1 is primarily configured of a wirelessantenna 21 which exchanges radio waves with the control device 3, awireless transmission/reception circuit 22 which subjects the radiowaves exchanged with the wireless antenna 21 to signal processing, anillumination device 23 of LEDs (Light-Emitting Diodes) or the like whichemits illumination light for illuminating the body cavity, anobservation device (imaging device) 24 for acquiring optical images ofthe body cavity illuminated with the illumination light from theillumination device 23 so as to take images, a digital signal processingcircuit 25 for performing digital signal processing or the like withregard to the imaging signals obtained from the imaging device 24, abattery unit 26 where a battery 26 a of some sort is stored, and aswitch 27 which turns electrical power supplied from the battery unit 26off and on.

The wireless transmission/reception circuit 22 selectively extractscarrier waves of the radio waves received from the control device 3using the wireless antenna 21, and performs detection, demodulation ofcontrol signals, and output thereof to the component circuits, as wellas modulating information signals such as video signals or the like fromthe component circuits with carrier waves of a predetermined frequency,and transmitting these from the wireless antenna 21 as radio waves.

The observation device 24 is configured of an object optical system 31for acquiring optical images, an imaging sensor 32 such as a CMOS(Complementary Metal-Oxide Semiconductor) or the like for imaging theoptical images acquired by the object optical system 31, and an imagingdriving circuit 33 for driving the imaging sensor 32.

The digital signal processing circuit 25 is configured of a digitalvideo signal processing circuit (hereafter referred to as “video signalprocessing circuit”) 34 which subjects the imaging signals taken by theimaging sensor 32 to signal processing and converts these into digitalvideo signals, and a digital compression processing circuit (hereafterreferred to as “compression processing circuit”) 35 which subjects theconverted digital video signals to compression processing.

The battery unit 26 supplies electric power from the stored battery 26 ato the illumination device 23, the digital signal processing circuit 25,and the wireless transmission/reception circuit 22 through the switch27. Note that the observation device 24 is supplied electric power fromthe battery 26 a via the digital signal processing circuit 25.

Also, the capsule-type medical device 1 has built in a permanent magnet(hereafter referred to simply as “magnet”) 36 upon which the rotatingmagnetic field, generated by the magnetic guiding device 5 as describedabove, acts. The magnet used there is a permanent magnet such as aneodymium magnet, samarium-cobalt magnet, ferrite magnet,iron-chromium-cobalt magnet, platinum magnet, Alnico (AlNiCo) magnet,and so forth.

Rare-earth magnets such as neodymium magnets and samarium-cobalt magnetshave strong magnetism and are advantageous in reducing the size of themagnet built into the capsule main unit 1A. On the other hand, ferritemagnet are advantageous in that the cost is low. Further, platinummagnets have excellent corrosion resistance, and are suitable formedical purposes.

Also, the magnet 36 built into the capsule main unit 1A needs not be apermanent magnet, and rather may be formed of a coil instead. In thiscase, the capsule main unit 1A may generate magnetism at the coil bycurrent from an electric power source such as a built-in battery or thelike, or the coil may be magnetized by electric power temporarily storedin an built-in capacitor or the like.

Further, instead of a built-in power source, the capsule main unit 1Amay have a coil built in which is used to generate electricity, which isstored in a capacitor and used to magnetize a separate coil. In thiscase, the limit on capacity of a built-in battery is done away with forthe capsule main unit 1A, thereby enabling operations over long periodsof time. Also, the same coil may be used for the coil for generatingelectricity and the magnetizing coil.

As shown in FIGS. 3A through 3C, the capsule-type medical device 1 has acylindrical capsule main unit 1A covered with a transparent main unitexterior member 41 in an airtight manner, with components built in suchas the above-described illumination device 23 and observation device 24being positioned within the cylindrical capsule main unit 1A. Morespecifically, the object optical system 31 making up the observationdevice 24 is positioned at the center portion of the tip side of thecylindrical capsule main unit 1A of the capsule-type medical device 1,and the imaging sensor 32 is positioned at the image focus location ofthe object optical system 31.

The imaging driving circuit 33 is formed so as to surround the imagingsensor 32. The digital signal processing circuit 25 is positioned at thebase side of the imaging driving circuit 33 and the imaging sensor 32,with the wireless transmission/reception circuit 22 disposed at the baseside of the digital signal processing circuit 25.

Also, the illumination device 23 is formed so as to surround the objectoptical system 31, thereby illuminating in front of the capsule mainunit 1A with illumination light through the transparent main unitexterior member 41. As shown in FIG. 3B, the illumination device 23 isconfigured of an array of four white LEDs, for example.

The battery unit 26 is provided on the rear side of the wirelesstransmission/reception circuit 22, with three batteries 36 a such asbutton batteries stored in the battery unit 26. Upon the battery unit 26being turned on by the switch 27 being operated externally, an operationwhich is not indicated in the drawings, electric power is supplied tothe illumination device 23 and the like through the switch 27. Themagnet 36 is positioned behind the battery unit 26, with the wirelessantenna 21 positioned further behind.

The capsule-type medical device 1 has the above-described built-incomponents reinforced and held by a cylindrical member such as a metalring reinforcing member not shown in the drawings, and placed in themain unit exterior member 41. The capsule-type medical device 1 isformed to a size wherein the patient 2 can swallow the capsule main unit1A without much trouble.

Also, the capsule-type medical device 1 has the magnet 36 disposedtherein such that the poles N and S are perpendicular to the center axis38 in the longitudinal direction of the cylindrical shape of the capsulemain unit 1A, as shown in FIG. 3A (i.e., in FIG. 3A, the center axis 38is horizontal, and the direction of magnetic polarity is vertical, whichis perpendicular thereto).

Thus, with the capsule-type medical device 1, upon the rotating magneticfield generated by the magnetic guiding device 5 acting upon the magnet36, the capsule main unit 1A rotates on the longitudinal center axis 38due to the magnet 36 being acted upon.

Also, the capsule-type medical device 1 is provided with a propulsiongenerating unit on the outer perimeter of the capsule main unit 1A,which is a spiral portion 37 made up of spiral grooves 37 a throughwhich fluids such as gas and liquids in the body cavity can flow throughin either direction, and spiral ridges 37 b where portions next to thespiral grooves 37 a protrude in a spiraling manner. Note that the spiralridges 37 b are formed with curved faces so as to smoothly come intocontact with the inner walls of the body cavity.

Providing such a spiral portion 37 allows the capsule-type medicaldevice 1 to move forward or backwards according to rotations of thecapsule main unit 1A, since rotations are converted into propulsionforce as the fluids such as gas and liquids in the body cavity passthrough the spiral grooves 37 a making up the spiral portion 37.

Also, the capsule main unit 1A can be propelled following the spiralsupon rotation, by using the friction between the protrusions of thespiral ridges 37 b making up the spiral portion 37 and the mucousmembranes.

That is to say, in the event that the protrusions of the spiral ridges37 b come into contact with the inner walls, and the capsule main unit1A is rotated in that state, the capsule main unit 1A rotates in a statewherein spinning free is restricted by the friction at the point ofcontact, so the rotations propel the capsule main unit 1A in spiralfashion as to the inner walls. Reversing the direction of rotationallows the direction or progression of the capsule main unit 1A to bereversed.

Let us say that the spiral protrusions formed for the spiral ridges 37 bare cyclically formed with a pitch of p, for example. In a normal stateof use wherein the spiral ridges 37 b are in contact with the tubularinner walls, one rotation of the capsule main unit 1A propels thecapsule main unit 1A by the pitch p.

Note that the capsule-type medical device 1 is capable of changing thedirection in which it is traveling according to the direction ofrotation in which the capsule main unit 1A rotates so as to match therotating plane of the magnet 36 and the rotating plane of the rotatingmagnetic field according to the rotation of the rotating magnetic field.

Generally, with such a capsule-type medical device 1, the capsule mainunit 1A may make useless motions such as eccentric motion (zigzagging)unless the center of gravity is not generally upon the longitudinalcenter axis 38 of the capsule main unit 1A.

With the present embodiment, the capsule-type medical device 1 isconfigured such that the batteries 27 a such as button batteries or thelike, which are the heaviest built-in components, are positioned on thecenter axis 38 close to the center in the longitudinal direction, andthe center 36 a of the direction of magnetism of the magnet 36 ispositioned on the center axis 38 of the capsule main unit 1A, so thatthe center of gravity G of the capsule main unit 1A is generally on thecenter axis 38 of the capsule main unit 1A, as shown in FIG. 3A.

Also, the built-in components may be arranged so as to match the centerof gravity G of the capsule main unit 1A by changing the position of themagnet 36 shown in FIG. 3A such that the center 36 a of the direction ofmagnetism of the magnet 36 is positioned on the center axis 38 of thecapsule main unit 1A, as with the capsule-type medical device 1 shown inFIG. 3D.

Configuring the capsule-type medical device 1 thus enables smoothguiding to the target position through the tubular body cavity or lumenwithout useless motions such as eccentric movement (zigzagging) of thecapsule main unit 1A.

Next, the operations of the capsule-type medical device 1 according tothe present invention will be described.

As shown in FIG. 1, in the event that there is the need to observe abody cavity tract such as the stomach 51 for example, of the patient 2,for long periods of time, the operator has the patient swallow thecapsule-type medical device 1, and causes the device to pass through thestomach. Immediately prior to having the patient 2 swallow thecapsule-type medical device 1, the operator turns the switch 27 thereofon, so that electric power from the batteries 26 a in the battery unit26 is supplied to the illumination device 23, the observation device 24,the digital signal processing circuit 25, and the wirelesstransmission/reception circuit 22.

At the same time, the operator activates (turns on) the magnetic guidingdevice 5, and magnetically controls the capsule-type medical device 1with the rotating magnetic field generated by the magnetic guidingdevice 5 so that the capsule-type medical device 1 reaches the targetportion.

As described above, with the capsule-type medical device 1, upon therotating magnetic field generated by the magnetic guiding device 5acting upon the magnet 36, the capsule main unit 1A is rotated by theforce which the magnet 36 receives.

Then, the rotational force of the capsule main unit 1A is converted intopropulsion and the capsule-type medical device 1 proceeds forwards orretreats backwards, due to at least one of: fluids such as gas andliquids in the body cavity passing through the spiral grooves 37 a; andthe spiral ridges 37 b smoothly coming into contact with the inner wallsof the body cavity. Further, in the event that the capsule main unit 1Acomes into contact with the inner walls of the body cavity, the capsulemain unit 1A is held by friction between the mucous membranes on theinner walls of the body cavity and the spiral ridges 37 b, so rotationsin this state are converted into greater propulsion force for proceedingforwards or retreating backwards. The capsule-type medical device 1 iscapable of changing the direction in which it is traveling by thecapsule main unit 1A rotating with the rotating plane of the magnet 36matching the rotating plane of the rotating magnetic field, according tothe rotation of the rotating magnetic field.

Moreover, the capsule-type medical device 1 is capable of smoothlymoving through the lumen to the target position without the capsule mainunit 1A making useless motions such as eccentric movement.

The capsule-type medical device 1 passes through the oral cavity 52 andthe esophagus 53, and reaches the stomach 51. Now, the major axialdiameter of the esophagus 53 is 16 mm and the minor axial diameterthereof is 14 mm, for example, so the capsule-type medical device 1 caneasily pass through if formed with a generally circular cross-section 14mm or less in outer diameter.

In the event that there is the need to observe the inside of the stomach51, the operator performs input corresponding to a command for staringobservation, from a keyboard 12 for example of the control device 3.Control signals from this key input are emitted as radio waves from theexternal antenna 14 of the control device 3, and transmitted to thecapsule-type medical device 1.

The capsule-type medical device 1 detects operation-start signals fromthe signals received with the wireless antenna 21, and drives thewireless transmission/reception circuit 22, illumination device 23,observation device 24, and digital signal processing circuit 25.

The illumination device 23 emits illumination light in the direction ofthe field of view of the observation device 24, the optical image of therange of the field of view illuminated is imaged on the imaging sensor32 of the observation device 24, subjected to photo-electric conversion,and an imaging signal is output. This imaging signal is converted intodigital video signals at the video signal processing circuit 34 of thedigital signal processing circuit 25, subjected to compressionprocessing at the digital compression processing circuit 35 andmodulated at the wireless transmission/reception circuit 22, and emittedfrom the wireless antenna 21 as radio waves.

The radio waves are received with the external antenna 14 of the controldevice 3, demodulated with the reception circuit within the personalcomputer main unit 11, converted into digital signals with an A/Dconverter within the personal computer main unit 11, and stored inmemory, while also read out at a predetermined speed with an opticalimage taken with the imaging sensor 32 being displayed in color on themonitor 13. The operator can observe the inside of the stomach 51 of thepatient 2 by observing this image. The operator can further readilycontrol how the external magnetic field is applied so that the entirestomach region can be observed, using operating means such as a joystickprovided outside the body while observing the observation image. Theoptical image can also be recorded in an unshown image recording device.

Following observation of the stomach 51, the capsule-type medical device1 is magnetically guided by the rotating magnetic field formed by themagnetic guiding device 5 as described above, so as to pass from thestomach 51 through the duodenum 54, the small intestine and largeintestine which are not shown, and to be extracted from the anus. Duringthis time, the capsule-type medical device 1 can observe the interior ofthe entire digestive tract.

Due to the configuration of the present embodiment, the capsule-typemedical device 1 can suppress useless motions of the capsule main unit1A such as eccentric movement (zigzagging), enabling effective andsmooth propulsion through the lumen to beside the target portion.

Also, no useless motions means that the magnetic guidance of thecapsule-type medical device 1 is more effective, thus yielding the greatadvantage that one or both of the magnet 36 within the capsule and theexternal magnet or electromagnet can be reduced in size.

Also, the medical acts can be completed in a short time by propellingthe capsule-type medical device 1 smoothly and efficiently.

Also, the capsule-type medical device may be configured for spreadingmedicine, as shown in FIGS. 4A and 4B. That is to say, the capsule-typemedical device 60 is configured having a medicine spreading opening 61 aprovided at the tip side so as to enable spreading of medicine stored ina medicine storing unit 61 within the capsule main unit 60A.

Further, the capsule-type medical device 60 is configured to take bodyfluid samples. That is, the capsule-type medical device 60 is configuredhaving a body fluid injecting opening 62 a on the rear end so as to takesamples of body fluid into a body fluid storing unit 62 within thecapsule main unit 60A. Opening and closing of the openings 61 a and 62 ais performed by communication control from the control device 3. Thus,the capsule-type medical device 60 is capable of discharging andspreading medicine stored in the medicine storing unit 61 from themedicine spreading opening 61 a to a target portions, and also iscapable of taking samples of body fluid from the fluid injecting opening62 a into the body fluid storing unit 62.

Also, it is needless to say that the medicine storing unit 61 may storea hemostatic agent for stopping bleeding, a ferrofluid or fluorescentagent which is safe to use with human bodies to externally determinehemorrhaging portions, and so forth, besides storing medicine.

Also, the capsule-type medical device 60 may be arranged to mix medicinestored in the medicine storing unit 61 with the body fluid taken in fromthe fluid injecting opening 62 a, and ejecting and spreading thismixture from the medicine spreading opening 61 a.

Note that this capsule-type medical device 60 has a spiral portion 37formed on the outer perimeter of the capsule main unit, in the same wayas with the capsule-type medical device 1 shown in FIG. 3A. Also, thecapsule-type medical device 60 has the center of gravity thereofgenerally upon the longitudinal center axis 38.

Also, the capsule-type medical device 60 may be configured such that anelastic rubber cover having a spiral groove formed thereupon isdetachably mounted to the capsule main unit as an exterior member, asshown in FIGS. 5A and 5B. That is to say, as shown in FIG. 5A, thecapsule-type medical device 70 is configured such that an elastic rubbercover 71 having spiral grooves 69 a (see FIG. 5B) formed thereupon canbe detachably mounted to the capsule main unit 70A. Thus, thecapsule-type medical device 70 enables fluids such as gas and liquids inthe body cavity to pass through the spiral grooves 69 a of the elasticrubber cover 71 to the tip and rear sides thereof.

Also, the thick portions of the elastic rubber cover 71 having a shapelike a belt wound thereupon forms the spiral ridges 69 b, thus formingthe spiral portion 69.

The capsule-type medical device 70 has a treatment tool storing portion72 capable of therapy or treatment within the capsule main unit 70A, andhas a treatment tool opening 72 a formed on the tip thereof. Thistreatment tool opening 72 a is plugged with a soluble film such asgelatin which is digested by stomach fluid or a fatty acid which isdigested by intestinal fluid, for example. The capsule-type medicaldevice 70 is arranged to open the treatment tool opening 72 a whenreaching near the target portion.

The treatment tool 73 stored in the treatment tool storing portion 72 iscapable of extending the tip thereof from the treatment tool opening 72a and retracting therein, and can perform therapy or treatment on thetarget portion of the body cavity tract. The treatment tool 73 isoperated and controlled by communication control from the control device3. Specific operations of the treatment tool 73 may be carried out byoperating means such as an unshown joystick or mouse or the likeconnected to the personal computer main unit 11.

Note that in FIG. 5A, the treatment tool 73 shown is an injection needlecapable of injecting a hemostatic agent. With the capsule-type medicaldevice 70 in this case, upon confirmation of a hemorrhaging portion withan unshown blood sensor or the observation device 24, operations of thetreatment tool 73 such as the hemostatic agent injection needle storedin the capsule main unit 70A are instructed by communication controlfrom the control device 3, and a hemostatic agent such as ethanol or apowder medicine is spread onto the hemorrhaging portion, therebystopping the bleeding.

Furthermore, the capsule-type medical device 70 comprises an ultrasonicunit 74 capable of examinations in the capsule main unit. The ultrasonicunit 74 is configured of an unshown ultrasonic probe for transmittingand receiving ultrasonic waves and an ultrasonic control circuit forcontrolling and driving the ultrasonic probe.

The capsule-type medical device 70 has the ultrasonic probe disposed ina watertight manner such that an unshown acoustic lens unit ispositioned on the outer face of the rear end of the capsule main unit70A, such that a 360° ultrasonic tomographic image, for example, isobtained at the rear end side.

Then, with the capsule-type medical device 70, the ultrasonictomographic image data obtained is modulated at the wirelesstransmission/reception circuit 22 in the same manner as with theabove-described observation image, and is emitted as radio waves fromthe wireless antenna 21. Thus, the capsule-type medical device 70 iscapable of diagnosing whether or not there are abnormalities in thedepth-wise direction of deep portions in the body cavity wall, such asin the small intestine 55 or the like. In the event that thecapsule-type medical device 70 is configured to have the observationdevice 24 as well, both the surface and deep portions of the body cavitycan be diagnosed at once.

Also, the capsule-type medical device 70 is configured with the capsulemain unit 70A having connected thereto a string 75 formed of softplastic or the like, having sufficient softness, diameter, and strength,to allow the capsule-type medical device 70 to be extracted from thestomach or small intestine through the mouth, or the large intestinefrom the anus, following inspection, without damaging the mucousmembranes in the body cavity. The string 75 is formed in a soft fashionnot to impede the rotational progress of the capsule main unit 70A. Thestring 75 is used by fixing the base end outside of the body. Also, thecenter of gravity of the capsule-type medical device 70 generally isupon the center axis 38 in the longitudinal direction of the capsulemain unit 70A, as with in FIG. 3A and others.

The capsule-type medical device may be configured with the spiralportion 37 and the observation device 24 provided at the rear side ofthe capsule main unit in the direction of procession.

That is to say, the capsule-type medical device 80 shown in FIGS. 6A and6B comprises an exterior member 80B having a spiral portion 37detachably formed on the rear side of the capsule main unit 80A in thedirection of progression thereof (toward the left in FIG. 6A, in thiscase), as well as the observation device 24 along with the illuminationdevice 23 in the backwards direction as to the direction of progressionof the capsule main unit 80A.

Also, the capsule-type medical device 81 shown in FIGS. 7A and 7Bcomprises multiple magnets 36, and the magnets may be placedsymmetrically across the longitudinal center axis 38 of the capsule mainunit 81A. As with the capsule-type medical device 80, this capsule-typemedical device 81 may be formed such that the exterior member 81Bprovided with the spiral portion 37 to the capsule main unit 81A isdetachable.

Also, as shown in FIGS. 8A and 8B, the capsule-type medical device maybe formed such that the exterior member 83B provided with the spiralportion 37 to the capsule main unit 83A in the direction of progressionthereof is detachable. Further, the observation device 24 may beprovided along with the illumination device 23 in the backwardsdirection as to the direction of progression of the capsule main unit83A.

Now, reference numeral 27B denotes a switch for tuning on and offelectric power supplied from the batteries 26 a in the battery unit 26.

The capsule-type medical device 83 shown in FIG. 8B has the magnet 36provided parallel to the longitudinal center axis 38 of the capsule mainunit 83A. The capsule-type medical device 83 comprises the digitalsignal processing circuit 25 and the wireless transmission/receptioncircuit 22 below the magnet 36.

Also, the capsule-type medical device 83 is arranged so as to berecovered by a capsule recovery tool 86 inserted into a treatment toolinsertion channel 85 of an endoscope 84, as shown in FIGS. 9A and 9B.

The endoscope 84 is arranged so that the capsule recovery tool 86 can beinserted through the treatment tool insertion channel 85. Referencenumeral 87 denotes an observation device provided to a distal end 84 aof the insertion portion of the endoscope 84. This observation device 87is configured of an object optical system 87 a and an imaging unit 87 bcomprising an imaging device provided at the imaging position of theobject optical system 87 a.

The capsule recovery tool 86 is formed as a flexible rod, with a magnet88 for recovering the capsule-type medical device 83 provided at the tipthereof. The capsule recovery tool 86 also has a recessed portion 89formed such that the spiral portion 37 of the capsule main unit 83A doesnot get in the way after the capsule-type medical device 83 is capturedby the magnet 88.

Also, an arrangement may be made wherein, as with the capsule-typemedical device 90 shown in FIG. 10A, the capsule main unit 90A can bedivided into the two portions of the portion where the observationdevice 24 is disposed, and the portion where the magnet 36 and thespiral portion 37 are provided. Thus, various combinations can be madefor the capsule-type medical device 90 according to the use; anarrangement wherein the field of view of the observation device 24 isbackwards as shown in FIG. 10A, an arrangement wherein the field of viewof the observation device 24 is diagonally backwards as shown in FIG.10B, and an arrangement wherein the field of view of the observationdevice 24 is sideways as shown in FIG. 10C.

Also, the capsule-type medical device may be arranged such that aportion having the spiral portion 37 is formed of a flexible member suchas elastic rubber or the like, as shown in FIG. 11A, so as to form aflexible insertion portion to be inserted into the body cavity.

That is, with the capsule-type medical device 100 as shown in FIG. 11A,the portion provided with the spiral portion 37 may be formed as aflexible insertion portion (a flexible soft portion) 101 formed of along and small-diameter flexible member, provided at one end of therigid capsule main unit 100A, with two magnets 36 a and 36 bsymmetrically disposed across the longitudinal center axis 38.

With this capsule-type medical device 100, the flexible insertionportion 101 has the same outer diameter as the outer diameter of one endof the generally-cylindrical capsule main unit 100A to which it isfastened by screwing, and the tip (end) side of the flexible insertionportion 101 is narrower than this outer diameter.

In this case, as shown in FIG. 11B, the capsule-type medical device 100has the illumination device 23 thereof configured of multiple LEDsdisposed in a ring-like shape around the observation device 24.

Also, an arrangement may be made with a ring-shaped magnet 36, as withthe capsule-type medical device 100′ having the flexible insertionportion 101 as shown in FIGS. 12A and 12B. With this capsule-typemedical device 100′, the base end of the flexible insertion portion 101is connected to the rigid capsule main unit 100A by fitting or pressing.

Also, instead of providing the spiral portion 37 on the flexibleinsertion portion 101, an arrangement may be made wherein the spiralportion 37 is provided on the rigid portion toward the rear on the sideopposite to the flexible insertion portion 101 to which the flexibleinsertion portion 101 is connected (in the event that the flexibleinsertion portion 101 is at the front in the direction of advancing), aswith the flexible insertion portion 101 as with the capsule-type medicaldevice 110 shown in FIGS. 13A through 13C. In FIGS. 13A through 13C, thedirection of advancing to the left, and the right side is the rear. Thecapsule-type medical device is swallowed, or inserted from the anus intothe large intestine, so as to head in the direction of advancing.

In this case, various combinations can be made for the capsule-typemedical device 110 according to the use; an arrangement wherein thefield of view of the observation device 24 is backwards as shown in FIG.13A, an arrangement wherein the field of view of the observation device24 is diagonally backwards as shown in FIG. 13B, and an arrangementwherein the field of view of the observation device 24 is sideways asshown in FIG. 13C. That is to say, the flexible insertion portion 101and the rigid capsule main unit 110A are separable.

With the capsule-type medical device 110 shown in FIG. 13A, the spiralportion 37 is provided over almost the entire perimeter of the rear sideof the capsule main unit 110A. Also, with the capsule-type medicaldevice 110 shown in FIG. 13B, the spiral portion 37 is provided overhalf of the rear side of the capsule main unit 110A in a diagonalmanner, so as to allow observation in the diagonally backwardsdirection. Also, with the capsule-type medical device 110 shown in FIG.13C, the spiral portion 37 is provided over half of the rear side of thecapsule main unit 110A, so as to allow sideways observation.

Also, the capsule-type medical device may have a configuration whereinthe flexible insertion portion is detachably mountable to the capsulemain unit as shown in FIG. 14A. That is to say, with the capsule-typemedical device 120 shown in FIG. 14A, the flexible insertion portion 121is detachably mountable to the capsule main unit 120A.

The flexible insertion portion 121 is soft, and thus easily bendable asshown in FIG. 14B. The flexible insertion portion 121 has a structurewhich is not readily stretched or compressed in the longitudinaldirection, but readily bends in the direction generally orthogonal tothe longitudinal direction.

Note that though the present embodiment has a wireless antenna 21 forperforming transmission and reception with the control device 3, thusconfiguring a capsule-type medical device capable of examination,therapy, and/or treatment by passing through the body cavity under thecontrol of the control device 3, the present invention is by no meansrestricted to this arrangement, and rather may be formed as acapsule-type medical device which is not provided with a wirelessantenna 21 and wherein information (data) such as optical images areextracted following passing through the body cavity tract and beingrecovered outside of the body.

Second Embodiment

A second embodiment of the present invention will be described withreference to FIGS. 15 through 21. The present embodiment has been madeto serve the same purpose as that of the first embodiment. The presentembodiment also aims to pass through bent body cavity portions moresmoothly.

The second embodiment comprises a flexible insertion portion (flexiblesoft portion), detachably mounted to a rigid capsule main unit. Otherconfigurations are approximately the same as the first embodiment, sothe same components will be denoted with the same reference numerals,and detailed description thereof will be omitted.

With the capsule-type medical device 150 according to the secondembodiment as shown in FIG. 15, the bendable flexible insertion portion151 is formed so as to be even longer and smaller in diameter than theflexible insertion portion 101 shown in FIG. 11A, for example, and isdetachably mounted to the rigid capsule main unit 150A.

The flexible insertion portion 151 formed of elastic rubber or the likehas the magnet 36 built in so as to be positioned on the longitudinalcenter axis 38, and has on the base side thereof a mounting portion 151a so as to be mounted onto the capsule main unit 150A. The flexibleinsertion portion 151 is mounted onto the capsule main unit 150A, thusconfiguring the capsule-type medical device 150.

In this case, the diameter Da of a recessed portion provided on themounting portion 151 a at the base side of the flexible insertionportion 151 is smaller than the diameter Db of the capsule main unit150A, so that this recessed portion can be elastically attached to thecapsule main unit 150A.

Also, the capsule-type medical device 150 is configured with the centerof gravity G thereof generally matching the longitudinal center axis 38of the capsule main unit 150A, as with the first embodiment (see FIG.16).

Also, as with the case of the flexible insertion portion 101, theflexible insertion portion 151 is configured so as to be bendable in thedirection orthogonal to the longitudinal direction, with the sideportion thereof being formed smaller in diameter than the outer diameterof the capsule main unit 150A, so as to have functions of bendingfollowing the bending body cavity tract such that the capsule main unit150A at the rear end can smoothly proceed, as specifically indicated inFIG. 18.

Accordingly, the capsule-type medical device 150 moves through the bodycavity with the flexible insertion portion 151 exploring the way toproceed, as shown in FIG. 16.

Now, the capsule-type medical device 150 may be configured so that, withregard to the maximum diameter L of a lumen organ such as the largeintestine or the like, the relation between the rigid length L1 of therigid capsule main unit 150A and the soft length L2 of the soft flexibleinsertion portion 151 is in the range of L1<L<L1+L2 as shown in FIG. 17.

In this case, the capsule-type medical device 150 is longer than themaximum diameter L of the lumen organ and moreover the length of therigid portion is short, so the direction thereof does not change in thelumen, and further, rotations from the magnet 36 are converted directlyinto propulsion, so the rotational force can be efficiently convertedinto propulsion, and smoothly move through the lumen.

Also, the capsule-type medical device 150 rotates due to the magnet 36at bent and narrow portions in the lumen such as the small intestine andlarge intestine as shown in FIG. 18, with the flexible insertion portion151 finding its way ahead, and the capsule main unit 150A following theflexible insertion portion 151 can readily pass through, as well.

Accordingly, with the present embodiment, eccentric movement can besuppressed, and the capsule-type medical device 150 can be smoothlypropelled to the target portion, as with the first embodiment. In thiscase, the flexible insertion portion 151 is formed even longer andsmaller in diameter, so eccentric movement can be suppressed evenfurther.

With the present embodiment, the flexible insertion portion 151 at thetip bends following the shape of bent tract in the lumen, and thus actsto allow the trailing capsule main unit 150A to change direction so asto smoothly pass. The capsule-type medical device 150 thus smoothlypasses through bent lumen portions as well, thereby reducing the timefor medical examination and/or treatment.

Also, an arrangement may be made wherein a wire-like member 162 is fixedby adhesions to the outer perimeter of the flexible insertion portion161 to form the spiral portion 37, as with the capsule-type medicaldevice 160 shown in FIG. 19. With such an arrangement for thecapsule-type medical device 160, the spiral portion 37 can be readilyprovided to the flexible insertion portion 161. The wire-like member 162may be formed of an elastic member such as rubber, shaped into awire-like form.

Also, an arrangement may be made for the capsule-type medical device 170wherein multiple ball-shaped magnets 172 a are built into the flexibleinsertion portion 171 so as to form multiple ball-shaped protrusions172, as shown in FIG. 20. The flexible insertion portion 171 is soft, sothe capsule-type medical device 170 can go to the depths of bentportions in the tubular organs such as the small intestine or largeintestine, while rotating, as indicated in FIG. 21.

Third Embodiment

A third embodiment of the present invention will be described withreference to FIGS. 22 and 23. The primary objects of the presentembodiment are approximately the same as those of the first and secondembodiments. Also, the present embodiment also aims to enable medicalexamination and/or treatment to be performed even more efficiently.

With the third embodiment, two capsule main units are provided, aleading-side rigid portion and a trailing-side rigid portion, with thetwo rigid portions being connected with a string-like material coveredwith a soft elastic materials such as urethane or silicon rubber or thelike which smoothly changes external form as shown in the drawings, forexample. Other configurations are approximately the same as the firstembodiment, so the same components will be denoted with the samereference numerals, and detailed description thereof will be omitted.

With the capsule-type medical device 200 according to the thirdembodiment, two capsule main units 200A are provided, a leading-siderigid portion 201 and a trailing-side rigid portion 202, with the tworigid portions 201 and 202 being connected with a string-like member 203as shown in FIG. 22. Also, the capsule-type medical device 200 isconfigured with the center of gravity G thereof generally matching thelongitudinal center axis 38 of the capsule main unit 200A, as with thefirst embodiment.

Also, the capsule-type medical device 200 comprises the spiral portions37 on both the leading-side rigid portion 201 and the trailing-siderigid portion 202. Further, the observation device 24 is configured soas to have a field of view looking diagonally forwards at the tip of thetrailing-side rigid portion 202.

According to such a configuration, the capsule-type medical device 200can obtain a good observation field of view even if in close contactwith the lumen.

That is to say, the capsule-type medical device 200 proceeds whilerotating, so the inner walls can be efficiently observed, and medicalexamination and/or treatment can be performed efficiently.

Also, with the capsule-type medical device 200, a portion of theprotrusions formed on the leading-side rigid portion 201 also come intothe field of view of the observation device 24, so a mark is made inthis field of view to indicate the position (polarity) of the magnet 36.

Also, an arrangement may be made for the capsule-type medical device 210wherein magnets 36, observation devices 24, and illumination devices 23,are provided to both the leading-side rigid portion 201 andtrailing-side rigid portion 202 provided with the spiral portions 37. Inthis case, propulsion can be generated for the capsule-type medicaldevice 210 as long as one of the spiral portions 37 comes into contactwith the inner walls of the lumen or with luminal fluids, regardless ofwhether the other spiral portion 37 is in contact with something.

This means that the capsule-type medical device 210 can be propelledefficiently, and medical examination and/or treatment can be performedefficiently. Also, providing observation means on both sides allowsmedical examination and/or treatment (image-taking, in this case) to beperformed even in the event that the image from one is insufficient, bycompensating with the image from the other. In order to expand thisfunction, an arrangement may be made wherein the observation andillumination range of the observation devices 24 and illuminationdevices 23 of the trailing-side rigid portion 202 is changed as to theobservation and illumination range of the observation devices 24 andillumination devices 23 of the leading-side rigid portion 201, forexample, widening the range as indicated by the dotted lines (only therange of observation is indicated, for sake of simplicity).

In this case, two types of imaged pictures with different observationranges are obtained, so medical examination and/or treatment can beperformed more efficiently.

According to the present invention described above, a capsule-typemedical device which can smoothly reach a target position through thelumen tract without useless motions such as eccentric movement can berealized. Further, according to the present invention, magnetic guidingefficiency is improved by reducing the unnecessary movement, so acapsule-type medical device wherein one or both of the magnet within thecapsule main unit and the external magnet can be reduced in size.

Having described the preferred embodiments of the invention referring tothe accompanying drawings, it should be understood that the presentinvention is not limited to those precise embodiments, and variouschanges, combinations, and modifications thereof could be made by oneskilled in the art without departing form the spirit or scope of theinvention as defined in the appended claims.

What is claimed is:
 1. A capsule type medical device comprising: aswallowable housing introduced into a subject a battery placed in thehousing; a magnet placed in the housing; and an antenna placed in thehousing and adapted to wirelessly communicate with a device locatedoutside the subject; wherein the magnet is arranged on a first side ofthe battery and the antenna is arranged on a second side substantiallyopposite to the first side with respect to the battery.
 2. The capsuletype medical device according to claim 1, wherein the capsule typemedical device further comprises an illumination device placed in thehousing, the illumination device being arranged on a substantiallyopposite side to the antenna with respect to the battery.
 3. The capsuletype medical device according to claim 1, wherein the magnet is providedwith one of a permanent magnet and a coil.
 4. A capsule type medicaldevice comprising: a swallowable housing introduced into a subject, thehousing having an axis in a first direction; and plural built-incomponents each disposed in the housing; wherein a heaviest component ofthe plural components is positioned on a central axis of the housinghaving substantially a same direction as the first direction such that acenter of gravity of the capsule type medical device is positioned onthe central axis of the housing.
 5. The capsule type medical deviceaccording to claim 4, wherein the heaviest component is positioned atthe center of the central axis such that the center of gravity of thecapsule type medical device is positioned at the center of the housing.6. The capsule typo medical device according to claim 4, wherein theheaviest component is a battery.
 7. The capsule type medical deviceaccording to claim 6, wherein the capsule type medical device furthercomprising a magnet disposed in the housing, the magnet being arrangedsuch that a center of a magnetism direction thereof is placedsubstantially on the central axis.
 8. The capsule type medical deviceaccording to claim 7, wherein the magnet is arranged so that themagnetism direction thereof has a direction substantially perpendicularto the central axis.
 9. The capsule type medical device according toclaim 6, wherein a magnet is further provided in the housing, the magnetbeing arranged such that a magnetism direction thereof has a directionsubstantially perpendicular to the central axis.
 10. The capsule typemedical device according to claim 6, wherein the battery comprisesplural button batteries.
 11. A capsule type medical device comprising: aswallowable housing having a longitudinal axis; a magnet disposed in thehousing and having a magnetism direction in a direction perpendicular tothe longitudinal axis; and a mark provided on the housing and adapted toindicate the magnetization direction.
 12. The capsule type medicaldevice according to claim 11, wherein the mark is adapted to indicateone of the poles of the magnet.
 13. The capsule type medical deviceaccording to claim 11, the magnet is provided with one of a permanentmagnet and a coil.
 14. The capsule type medical device according toclaim 11, further comprising a spiral provided on the housing.